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Without further feeding, they moult three times and eventually become adults. In females, which are close to spherical, feeding resumes and the reproductive system develops. [3] The life span of an adult female may extend to three months, and many hundreds of eggs can be produced.
The nematodes (/ ˈ n ɛ m ə t oʊ d z / NEM-ə-tohdz or NEEM-; Ancient Greek: Νηματώδη; Latin: Nematoda), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic.
The tra-1 is a gene within the TRA-1 transcription factor sex determination pathway that is regulated post-transcriptionally and works by promoting female development. [33] In hermaphrodites (XX), there are high levels of tra-1 activity, which produces the female reproductive system and inhibits male development.
Allantonematid nematodes infect insect larvae by piercing through the cuticle, after which they reside in the insect blood. There they develop through multiple juvenile stages before being shed out the anus or reproductive tracts. Mating typically occurs external to the insect host, after which mated female nematodes infect new hosts.
The spermatheca (pronounced / s p ər m ə ˈ θ iː k ə / pl.: spermathecae / s p ər m ə ˈ θ iː s iː /), also called receptaculum seminis (pl.: receptacula seminis), is an organ of the female reproductive tract in insects, e.g. ants, bees, [1] some molluscs, Oligochaeta worms and certain other invertebrates and vertebrates. [2]
Like all nematodes, it has four muscle bands that span the length of the body and has no devoted respiratory or circulatory system. [6] P. hermaphrodita has four larval stages before becoming a fully reproductive hermaphroditic adult female. [7]
The male reproductive system consists of a single testis, vas deferens, seminal vesicles, ejaculatory duct, two spicules, gubernaculum and bursa. Female reproductive organs include a pair of ovaries, oviducts, seminal receptacle, uteri and a long oviduct, vagina and vulva. The eggs are oval shaped, and enclosed in double egg membrane.
Mesorhabditis is a genus of nematodes. Species in the genus Mesorhabditis exhibit an unusual form of parthenogenesis, in which sperm-producing males copulate with females, but the sperm do not fuse with the ovum. Contact with the sperm is essential for the ovum to begin dividing, but because there is no fusion of the cells, the male contributes ...